Generally, a data center uses a fully-connected network structure to improve network communications efficiency. One type of fully-connected network structure may be as follows. Switches at different layers are connected in a pairwise mode, and each switch at the bottom layer is connected to a certain quantity of hosts. When a switch on a network receives a broadcast data packet, flooding needs to be performed on the broadcast data packet on all ports except a receiving port in a virtual local area network (VLAN) to which the switch belongs. However, when a loop exists on a fully-connected network, a broadcast data packet may be repeatedly broadcasted on the loop, which causes a broadcast storm.
The fully-connected network may be implemented based on a software defined network (SDN) technology. A network applying the SDN technology generally includes several network devices and a controller controlling the network devices. The core of the SDN is to separate a control plane of a network device (for example, a switch) from a data forwarding plane of the network device, where the data forwarding plane performs data forwarding based on a flow table, and the control plane provides an application programming interface (API) for the controller to perform control. On an SDN network, a routing table in a switch is empty at an initial stage. When a forwarding rule matching a received data packet cannot be found from the routing table of the switch, the switch requests a forwarding rule by reporting the data packet to a controller, forwards the data packet according to a forwarding rule delivered by the controller, and stores the forwarding rule in the routing table. Generally, the default forwarding rule delivered by the controller to the switch is broadcasting the data packet. Referring to FIG. 1, FIG. 1 is a schematic diagram of an SDN-based fully-connected network architecture. In FIG. 1, each S represents a switch, and there are two layers of switches, namely, core switches and access switches; each h represents a host connected to an access switch; and a controller is connected to each switch, switches at different layers are connected in a pairwise mode, and each access switch is connected to two hosts.
To avoid a broadcast storm, in the prior art, data on a network may be broadcasted over the Spanning Tree Protocol (STP). When STP is used, a network topology is constructed for switches on the network according to a tree structure; one switch is selected from the tree structure and is used as a root bridge device; all switches form a tree starting from the root bridge device; the root bridge device sends a configuration packet on a timed basis; after a non-root bridge device receives the configuration packet, the non-root bridge device re-calculates configuration information, and forwards the configuration packet. If a switch can receive the configuration packet from more than two ports, there is more than one transmission link from the switch to the root bridge device, and a forwarding loop is formed between the switch and the root bridge device. In this case, the switch selects one port and shields other ports, so as to eliminate the forwarding loop on the network.
During the study on the prior art, the inventor discovers that because a switch needs to avoid occurrence of a broadcast storm by shielding ports, forwarding capabilities of the ports on the network are suppressed, which is equivalent to that, for a fully-connected network, a quantity of available transmission links on the network is reduced, thereby reducing a utilization rate of the transmission links on the network.